In many large system applications, a plurality of power supplies, identical to each other, are positioned within close proximity to each other. A large number of circuit features and components may be duplicated in each power supply. These duplicated components are often expensive because of circuit accuracy and stability requirements. For example, a plurality of digitally controlled switching regulators such as disclosed in U.S. Pat. No. 4,095,165, issued to V. B. Boros on June 13, 1978, and assigned to the same assignee as this application, would all utilize a highly stable voltage controlled oscillator or some other type of analog-to-digital converter in order to assure accurate regulation. The cost of the individual regulators may be significantly reduced by using a less expensive voltage controlled oscillator. However, a less expensive voltage controlled oscillator tends to drift in frequency and reduces the precision of regulation of the switching regulator.
It is also frequently desirable to include auxiliary features in each regulator such as alarm circuits or sophisticated feedback systems that are not normally included because of cost.